Week 10: Exploring Precipitation Patterns

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Intro to Importing Data into Google Earth

As you learned in Week 9, Google Earth has a rich collection of built-in datasets that include current and historic aerial and satellite imagery, place names, travel information, 3D models, videos, articles, and more. Google Earth also allows users to create and import imagery and mappable data from a variety of different sources. top of page

KML and KMZ files

The default file type for spatial data in Google Earth is KML (Keyhole Markup Language) or KMZ (a compressed or "zipped" KML file). KML files are text-based and employ coding tags like to those used for XML or HTML programming. Google Earth processes KML files in a way that is similar to how web browsers process HTML and XML files. KML syntax tells Earth browsers like Google Earth and Google Maps how to display geographic features such as points, lines, images, polygons, and models. Each location included in a KML file must have assigned longitude and latitude coordinates. Other data can make the view more specific, such as tilt, heading, and/or altitude. Some KML files, like placemarks, ground overlays, paths, and polygons can be created directly in Google Earth. More complex KML elements must be created "by hand" using a text editor and require knowledge of KML tagging. When a text file is saved with a .kml or .kmz extension, Earth browsers like Google Earth know how to display it. KML files can be used for a wide variety of applications. You can placemark your home, school or favorite destination; plan or document a trip; map natural resources and scientific datasets; and explore the world, past and present.

You can view the KML "code" for any feature in Google Earth by simply right-clicking (CTRL + click on a Mac) that feature in the 3D Viewer of Google Earth and selecting Copy. Paste the contents of the clipboard into any text editor. The visual feature that you were viewing in Google Earth is converted into its KML text equivalent. If you're feeling ambitious, go ahead and experiment with this.

Tracks (or trackpoints)points automatically recorded by the GPS device periodically along a recorded route. Tracks can be imported into Google Earth as paths.

Waypointspoints entered manually by the user and typically marked with a name, such as "home" or "turnaround point."

Routespoints that the GPS device uses to create the routing, such as when you instruct the device to "go to" a recorded point from another recorded point. Routes can be imported into Google Earth as paths.

Imagery: There are two ways to import imagery into Google Earth:

PhotosYou can add photos to Google Earth to take people on a photographic tour. Photos from your hard drive or the Internet can be placed in a geographic location that you and other users can fly to and navigate.

Image overlaysImage overlays can be draped over the surface of the Earth (or appear elevated). Topographical maps, weather satellite image maps, or other geographical image data can be used as image overlays. Overlay images must have a North-Top orientation with simple cylindrical projection. Image overlay files may be hosted online or stored locally on your hard drive. When adding an image overlay from an online image, you must have the image's URL, and it must end in .jpg or another image file extension. When you create an image overlay, it conforms to the terrain or shape of the land beneath if the Terrain layer is turned on.

Take some time to browse through some of the many websites that offer Google Earth-compatible KML/KMZ data. Find and download at least one KML/KMZ file of interest to you, to import into Google Earth. Save KML/KMZ files to your Eyes in the Sky II Week 10 folder.

The Google Earth KML Gallery: The Google Earth Gallery contains hundreds of community-created KML files, including prepared tours, placemarks, scientific datasets, recent imagery, and 3D models. New content is added regularly, and is organized into categories for easy searching. As you saw in Week 9, you can access the Gallery directly from Google Earth by clicking on Add Content button in Places panel.

Google Earth Blog: The Google Earth Blog (not affiliated with Google) is a great place to find interesting news, images, and datasets for Google Earth. With the Google Earth Blog, you can download data, learn about Google Earth updates, find out about new technologies and features, and find links to other Google Earth web sites. Try using the Categories menu to search the blog by topic area.

To zoom to the photo, double click on the camera icon in the Places panel or in the 3D Viewer. You will be flown into the photo and the navigation tools in the 3D Viewer will change into photo navigation tools, so you can explore the photograph. Try zooming into and out of the photograph.

Try adding a photo of your choice to a different location in the 3D Viewer. Remember, photos can come from either your hard drive or the internet. A photo hosted online must have a url that ends in .jpg, .gif, or another image file extension. Use the Browse button in the New Photo dialog to navigate to images on your hard drive.

When the Image Overlay dialog box opens, click on the Description tab and give your image overlay the name Yosemite Hiking Trail.

Copy and paste http://www.localhikes.com/images/MSA_0000/YosemiteFalls/YosemiteFalls_Topo.Jpg into the Link text box. You will see green borders appear around the image. Use the center cross hairs to move the map, the edges and the corners to scale the map, and the left diamond to rotate the map. Use the slider to adjust the transparency of the map. This will help you properly align the map with the underlying satellite imagery. NOTE: Getting the exact right placement of an image overlay can be tricky. Be patient!